There have been many really creative apps iPhone/iPod touch which make it easy for an artist or designer to quickly sketch out ideas and concepts. iTracer is one of these apps. It allows you to create 3D models using basic primitives, revolutions and extrusions. While it is not as powerful as a full 3D modeling package, it is a great way to begin a model or to rapidly visualize an idea.
Step 1: Create a New File
To begin, select the File icon located at the top left of the screen and choose the New file option. Next, select the Reflection Sample option which will automatically load a preset model and lighting scheme. Tap the Object button on the bottom to allow you to manipulate the items in the modeling window, then double tap the objects themselves. This will select the objects and allow you to delete them, leaving a blank canvas. You can also choose the Empty Scene option which will give you a blank canvas to work from. Just be sure to add a light to the scene to make it easier to view the object you are about to create. Either way will work just as well as the other.
Step 2: Creating the Object
Choose the + button next to the File icon and select the Mesh option. Then choose the type of mesh you would like to create. In this example I decided to create a small vase or vessel using the Revolution command. After choosing the type of mesh object, iTracer will give you a grid that you can draw points on to create the profile of the object you would like to revolve. Draw the points and move them to your liking and when finished, tap the Accept button. This will create the revolved object and place it into the modeling scene.
Step 3: Exporting the Model
Once you are happy with the model, tap the File button and select the Export option. This will open a window that will allow you to email a .3ds file of your object to your recipient of choice.
Step 4: Converting the File and Printing the Object
Most 3D printing machines utilize .STL files and since iTracer exports .3ds files, your model needs to be converted. I used Meshlab, which is an open-source mesh editing tool for this process, but any 3D modeling program should capable of converting the .3ds to a .STL file. In Meshlab, open the .3ds file then go to File/Save As... and save the file an .STL or whichever file format you choose. From here you can send the model to a service bureau such as Shapeways to have it printed. Or to any other rapid prototyping machine such as a RepRap or Makerbot. I am fortunate enough to have access to a Dimension ABS printer, so I printed my model on that, but using a homemade printer would be much more rewarding.